1. Field of the Invention
The present invention relates to a method of discriminating the type of an optical disk and a reproducing apparatus thereof particularly suitable for use in a DVD-RW reproducing apparatus.
2. Description of Related Art
Owing to the diversification of a CD-ROM format and the advent of a DVD (digital versatile disk), various types of optical disks appear and they tend to increase in the future. Currently, in the category of the CD-ROM format, there are a CD-ROM for read only and a CD-R on which writing is possible. In the category of the DVD, there are a DVD-ROM (also including a DVD-Video) for read only, a DVD-R and a DVD-RW in which the allowable number of times of rewriting is one and finite respectively, and a DVD-RAM capable of reading/writing any times.
The above-mentioned DVD-R is not different from the DVD-ROM (also including the DVD-Video) with respect to the point that wobble and land prepit are adopted as the track format and data is recorded on the land portion of the disk. Data such as address information and so on are recorded on this land portion, and, by utilizing this, a drive can know accurate positional information on the data. Thus, when data is additionally written, recording can be performed with high accuracy.
A standard developed using this DVD-R as the base so that data can be written and erased (additional writing) is the DVD-RW. Currently, in the place of the DVD forum, an arranging work for the DVD-RW of version 1.0 standard is in progress. The DVD-RW is sequential writing and the physical specifications are substantially the same as those of the DVD-R. For the future, it is provided as a DVD-R/RW drive and both media of the DVD-R and the DVD-RW can be read/written by a single drive.
Incidentally, in a conventional DVD-RW reproducing apparatus, upon reproducing, by searching a data area formatted at a slightly outer peripheral position of a physical sector number xe2x80x9c30000hxe2x80x9d (sector number) allocated as a lead-in area, it is started, and, when the loaded disk is judged as the DVD, it searches xe2x80x9c2F200hxe2x80x9d to obtain control data. These format information will be described later with reference to FIG. 3.
However, in the above-mentioned DVD-RW of version 1.0, since data allocated to the control data zone of xe2x80x9c2F200Hxe2x80x9d to xe2x80x9c2FE00hxe2x80x9d is recorded as data which cannot be read/written by emboss pits, search to this area is impossible.
For example, in case of recording data actually readable to the control data zone as the DVD-ROM (also including the DVD-Video) or the DVD-R, according to the DVD-RW following the DVD-RW of version 1.0, land prepit (guide signal) is in the land portion, and, due to the presence of this portion, data in the control data zone can not be read. Therefore, it becomes hard to reproduce each medium of the DVD-RW and the DVD-R or the DVD-ROM (also including the DVD-Video) by a single reproducing apparatus.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of discriminating a type of optical disks which can also discriminate a DVD-RW of version 1.0, in which, when a medium loaded in a reproducing apparatus is judged as a DVD, by detecting the presence or absence of wobble, searching a control data area if the wobble is not present, if present, searching an RW physical format information zone to confirm type information, if the type information is the DVD-RW, searching again the data area to perform reproduction, judging as a DVD-R if all are xe2x80x9c0xe2x80x9d, searching a control data zone to confirm the DVD-R, and then reproducing, with avoiding access to an unreadable zone, the compatibility with disks in conventional versions including the DVD-R or a DVD-ROM (also including a DVD-Video) can be maintained, and a reproducing apparatus thereof.
In order to solve the above problem, according to the first aspect of the present invention, there is provided a method of discriminating a type of disk for discriminating disk type between a first disk in which a first area in a lead-in area has an unreadable area and disk type information is recorded in a readable second area different from the first area, and a second disk in which disk type information is recorded in a readable first area in a lead-in area, the method comprising detecting the presence or absence of wobble at a predetermined position on a disk; and, when the wobble is not detected, searching the first area to read the disk type information, and, when the wobble is detected, searching the second area to read the disk type information, thereby discriminating the disk type.
According to the second aspect of the present invention, in the above method, the first area is a control data zone, the second area is an RW physical format information zone, the first disk is a DVD-RW, and the second disk is a DVD-R, and the method comprises, when the wobble is not detected, searching the control data zone to read disk type information, and judging whether or not the disk type is a DVD-ROM (also including DVD-Video); and, when the wobble is detected, searching the RW physical format information zone to read the record information, when the record information is 0, searching the control data zone to read the disk type information, and judging whether or not the disk type information is the DVD-R.
According to the third aspect of the present invention, in the method according to the first aspect of the present invention, the first area is a control data zone, the second area is an RW physical format information zone, the first disk is a DVD-RW, and the second disk is a DVD-ROM (also including a DVD-Video), and the method comprises, when the wobble is not detected, searching the control data zone, and judging whether or not the disk type is a DVD-ROM (also including a DVD-Video); and, when the wobble is detected, searching the RW physical format information zone to read the disk type information, and judging whether or not the disk type is the DVD-RW.
According to the fourth aspect of the present invention, there is provided a reproducing apparatus which can reproduce a first disk in which a first area in a lead-in area has an unreadable area and disk type information is recorded in a readable second area different from the first area, and a second disk in which disk type information is recorded in a readable first area in a lead-in area, the apparatus comprising a wobble detection section for detecting the presence or absence of wobble; a disk type information reading section for, when the wobble is not detected, searching the first area to read the disk type information, and, when the wobble is detected, searching the second area to read the disk type information; and a reproduction control section for performing a reproduction operation in accordance with the disk type information.
According to the fifth aspect of the present invention, in the apparatus according to the fourth aspect of the present invention, the first area is a control data zone, the second area is an RW physical format information zone, the first disk is a DVD-RW, and the second disk is a DVD-R, and the reproduction control section, when the wobble is not detected, searches the control data zone to read the disk type information, and, after confirming the disk type to be DVD-ROM (also including a DVD-Video), performs reproduction, and, when the wobble is detected, searches the RW physical format information zone to read the record information, when the record information is 0, searches the control data zone to read the disk type information, and, after confirming that the disk type information is the DVD-R, performs reproduction.
According to the sixth aspect of the present invention, in the apparatus according to the fourth aspect of the present invention, the first area is a control data zone, the second area is an RW physical format information zone, the first disk is a DVD-RW, and the second disk is a DVD-ROM (also including a DVD-Video), and the reproduction control section, when the wobble is not detected, searches the control data zone to read the disk type information, and, after confirming that the disk type is the DVD-ROM (also including the DVD-Video), performs reproduction, and, when the wobble is detected, searches the RW physical format information zone to read the disk type information, and, after confirming that the disk type information is the DVD-RW, performs reproduction.
According to the above construction, the DVD-ROM (also including the DVD-Video) or the DVD-R/RW drive in which the DVD-ROM (also including the DVD-Video) or both media of the DVD-R and the DVD-RW can be read/written by a single drive can be provided, and thereby the compatibility with disks in the conventional versions including the DVD-ROM (also including the DVD-Video) or the DVD-R can be maintained.